topic Python value variable in SQL expression FeatureLayer.query(where = "attributeName = 'StringValue'" ) in ArcGIS API for Python Questions

Python value variable in SQL expression FeatureLayer.query(where = "attributeName = 'StringValue'" )

AngelRomoSandoval — Tue, 13 Sep 2022 10:11:52 GMT

Hello,

I am trying to insert a variable where ClientName is written:

Fl_Filtered = FeatureLayer.query(where = "client = 'clientName'")

I tried this without success:

querytxt = 'where = "KundeName = ' + "'" + ""'%s'"" %kundeNameWhereFilter + "'" + '"' Print(querytxt) Fl_Filtered = FeatureLayer.query(querytxt)

The print ist returns the right String but the query returns an Error code: 400

Anyone knows how could be the solution?

Thanks

Re: Python value variable in SQL expression FeatureLayer.query(where = "attributeName = 'StringValue'" )

Clubdebambos — Tue, 13 Sep 2022 10:26:45 GMT

Hi @AngelRomoSandoval

I like to use the string format, there are various options, see here.

The example below uses numbered indexes.

## example 1 client_name = "My Clients Name" Fl_Filtered = FeatureLayer.query(where = "client = '{0}'".format(client_name) ### DO SOMETHING WITH THE CLIENT ## example 2 client_list = ["Client 1", "Client 2", "Client 3"] for client_name in client_list: Fl_Filtered = FeatureLayer.query(where = "client = '{0}'".format(client_name) ### DO SOMETHING WITH EACH INDIVIDUAL CLIENT

also, how are you accessing the Feature Layer?

from arcgis import GIS agol = GIS("home") feature_service = agol.content.get("***ITEM_ID***") feature_layer = feature_service.layers[0] # where 0 is the index of the first layer in the featire service client_name = "My Clients Name" Fl_Filtered = feature_layer.query(where = "client = '{0}'".format(client_name)

Re: Python value variable in SQL expression FeatureLayer.query(where = "attributeName = 'StringValue'" )

AngelRomoSandoval — Tue, 13 Sep 2022 11:22:35 GMT

Yes, I access with the Item Id. Thank you for all the examples!

Re: Python value variable in SQL expression FeatureLayer.query(where = "attributeName = 'StringValue'" )

DavidAnderson_1701 — Mon, 19 Sep 2022 14:14:10 GMT

Be careful when doing this if the variable value is coming from an outside source. A SQL injection attack could be done. Before deploying the simple solution read a bit more about SQL injection attacks and how to defend your code against them. Here is one source, https://realpython.com/prevent-python-sql-injection/, many others to consult.

Re: Python value variable in SQL expression FeatureLayer.query(where = "attributeName = 'StringValue'" )

KimOllivier — Tue, 04 Oct 2022 23:01:54 GMT

There is already a function to validate the SQL string built in to the API. Very straightforward.

https://developers.arcgis.com/python/api-reference/arcgis.features.html#arcgis.features.FeatureLayer.validate_sql

Re: Python value variable in SQL expression FeatureLayer.query(where = "attributeName = 'StringValue'" )

AngelRomoSandoval — Fri, 11 Nov 2022 09:08:34 GMT

Thank you for the info, no, it comes not from an external source. I will keep it in mind.